EP0289036A1 - Preparation of 3-chloro-4,5-difluorobenzotrifluoride - Google Patents
Preparation of 3-chloro-4,5-difluorobenzotrifluoride Download PDFInfo
- Publication number
- EP0289036A1 EP0289036A1 EP88106896A EP88106896A EP0289036A1 EP 0289036 A1 EP0289036 A1 EP 0289036A1 EP 88106896 A EP88106896 A EP 88106896A EP 88106896 A EP88106896 A EP 88106896A EP 0289036 A1 EP0289036 A1 EP 0289036A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- chloro
- reaction
- difluorobenzotrifluoride
- celsius
- preparation
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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- RZMVFJHGONCXQR-UHFFFAOYSA-N 1-chloro-2,3-difluoro-5-(trifluoromethyl)benzene Chemical compound FC1=CC(C(F)(F)F)=CC(Cl)=C1F RZMVFJHGONCXQR-UHFFFAOYSA-N 0.000 title claims abstract description 22
- 238000002360 preparation method Methods 0.000 title claims description 16
- SECXISVLQFMRJM-UHFFFAOYSA-N N-Methylpyrrolidone Chemical compound CN1CCCC1=O SECXISVLQFMRJM-UHFFFAOYSA-N 0.000 claims abstract description 12
- BWQFQKZDLBJZAW-UHFFFAOYSA-N 1,3-dichloro-2-fluoro-5-(trifluoromethyl)benzene Chemical compound FC1=C(Cl)C=C(C(F)(F)F)C=C1Cl BWQFQKZDLBJZAW-UHFFFAOYSA-N 0.000 claims abstract description 9
- 238000000034 method Methods 0.000 claims description 20
- NROKBHXJSPEDAR-UHFFFAOYSA-M potassium fluoride Chemical compound [F-].[K+] NROKBHXJSPEDAR-UHFFFAOYSA-M 0.000 claims description 14
- 239000011698 potassium fluoride Substances 0.000 claims description 11
- XJHCXCQVJFPJIK-UHFFFAOYSA-M caesium fluoride Chemical compound [F-].[Cs+] XJHCXCQVJFPJIK-UHFFFAOYSA-M 0.000 claims description 8
- 235000003270 potassium fluoride Nutrition 0.000 claims description 7
- 238000010992 reflux Methods 0.000 claims description 4
- 238000004821 distillation Methods 0.000 claims description 3
- 238000006243 chemical reaction Methods 0.000 abstract description 17
- 239000006227 byproduct Substances 0.000 abstract description 8
- 230000015572 biosynthetic process Effects 0.000 abstract description 7
- 238000004519 manufacturing process Methods 0.000 abstract description 4
- KJOHHPPNYVMWRE-UHFFFAOYSA-N 1,2,3-trifluoro-4-(trifluoromethyl)benzene Chemical compound FC1=CC=C(C(F)(F)F)C(F)=C1F KJOHHPPNYVMWRE-UHFFFAOYSA-N 0.000 abstract description 3
- 239000000463 material Substances 0.000 abstract description 3
- 238000003786 synthesis reaction Methods 0.000 abstract description 3
- 239000000047 product Substances 0.000 description 8
- WIMUDCCCIFLMQO-UHFFFAOYSA-N 1,2,3-trifluoro-5-(trifluoromethyl)benzene Chemical compound FC1=CC(C(F)(F)F)=CC(F)=C1F WIMUDCCCIFLMQO-UHFFFAOYSA-N 0.000 description 6
- 238000005755 formation reaction Methods 0.000 description 4
- 239000011541 reaction mixture Substances 0.000 description 4
- 239000007858 starting material Substances 0.000 description 4
- FBKFIAIRSQOXJR-UHFFFAOYSA-N 1,2,3-trichloro-5-(trifluoromethyl)benzene Chemical compound FC(F)(F)C1=CC(Cl)=C(Cl)C(Cl)=C1 FBKFIAIRSQOXJR-UHFFFAOYSA-N 0.000 description 3
- ZMXDDKWLCZADIW-UHFFFAOYSA-N N,N-Dimethylformamide Chemical compound CN(C)C=O ZMXDDKWLCZADIW-UHFFFAOYSA-N 0.000 description 3
- USIUVYZYUHIAEV-UHFFFAOYSA-N diphenyl ether Chemical class C=1C=CC=CC=1OC1=CC=CC=C1 USIUVYZYUHIAEV-UHFFFAOYSA-N 0.000 description 3
- 230000007613 environmental effect Effects 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- HXJUTPCZVOIRIF-UHFFFAOYSA-N sulfolane Chemical compound O=S1(=O)CCCC1 HXJUTPCZVOIRIF-UHFFFAOYSA-N 0.000 description 3
- -1 3,5-dichloro-4-fluorobenzotrifluoride compound Chemical class 0.000 description 2
- ODGIMMLDVSWADK-UHFFFAOYSA-N 4-trifluoromethylaniline Chemical compound NC1=CC=C(C(F)(F)F)C=C1 ODGIMMLDVSWADK-UHFFFAOYSA-N 0.000 description 2
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 2
- IAZDPXIOMUYVGZ-UHFFFAOYSA-N Dimethylsulphoxide Chemical compound CS(C)=O IAZDPXIOMUYVGZ-UHFFFAOYSA-N 0.000 description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 2
- 229910001515 alkali metal fluoride Inorganic materials 0.000 description 2
- 238000009835 boiling Methods 0.000 description 2
- 125000001309 chloro group Chemical group Cl* 0.000 description 2
- 238000006193 diazotization reaction Methods 0.000 description 2
- KZTYYGOKRVBIMI-UHFFFAOYSA-N diphenyl sulfone Chemical compound C=1C=CC=CC=1S(=O)(=O)C1=CC=CC=C1 KZTYYGOKRVBIMI-UHFFFAOYSA-N 0.000 description 2
- 230000002363 herbicidal effect Effects 0.000 description 2
- 238000000926 separation method Methods 0.000 description 2
- 239000002904 solvent Substances 0.000 description 2
- HHVIBTZHLRERCL-UHFFFAOYSA-N sulfonyldimethane Chemical compound CS(C)(=O)=O HHVIBTZHLRERCL-UHFFFAOYSA-N 0.000 description 2
- OADFVSQNTMBILE-UHFFFAOYSA-N 1,2-difluoro-3-nitro-5-(trifluoromethyl)benzene Chemical compound [O-][N+](=O)C1=CC(C(F)(F)F)=CC(F)=C1F OADFVSQNTMBILE-UHFFFAOYSA-N 0.000 description 1
- MBDUIEKYVPVZJH-UHFFFAOYSA-N 1-ethylsulfonylethane Chemical compound CCS(=O)(=O)CC MBDUIEKYVPVZJH-UHFFFAOYSA-N 0.000 description 1
- VWCFQNQVNVMFGV-UHFFFAOYSA-N 1-octylsulfinyloctane Chemical compound CCCCCCCCS(=O)CCCCCCCC VWCFQNQVNVMFGV-UHFFFAOYSA-N 0.000 description 1
- BQCCJWMQESHLIT-UHFFFAOYSA-N 1-propylsulfinylpropane Chemical compound CCCS(=O)CCC BQCCJWMQESHLIT-UHFFFAOYSA-N 0.000 description 1
- ITNMAZSPBLRJLU-UHFFFAOYSA-N 2,6-dichloro-4-(trifluoromethyl)aniline Chemical compound NC1=C(Cl)C=C(C(F)(F)F)C=C1Cl ITNMAZSPBLRJLU-UHFFFAOYSA-N 0.000 description 1
- DBXGGVURUQFFGT-UHFFFAOYSA-N 2-chloro-1,3-difluoro-5-(trifluoromethyl)benzene Chemical compound FC1=CC(C(F)(F)F)=CC(F)=C1Cl DBXGGVURUQFFGT-UHFFFAOYSA-N 0.000 description 1
- HFHAVERNVFNSHL-UHFFFAOYSA-N 2-chloro-1,3-dinitro-5-(trifluoromethyl)benzene Chemical compound [O-][N+](=O)C1=CC(C(F)(F)F)=CC([N+]([O-])=O)=C1Cl HFHAVERNVFNSHL-UHFFFAOYSA-N 0.000 description 1
- NVHWZCIXUHFQGS-UHFFFAOYSA-N 2-fluoro-1,3-dinitro-5-(trifluoromethyl)benzene Chemical compound [O-][N+](=O)C1=CC(C(F)(F)F)=CC([N+]([O-])=O)=C1F NVHWZCIXUHFQGS-UHFFFAOYSA-N 0.000 description 1
- VLRGXXKFHVJQOL-UHFFFAOYSA-N 3-chloropentane-2,4-dione Chemical compound CC(=O)C(Cl)C(C)=O VLRGXXKFHVJQOL-UHFFFAOYSA-N 0.000 description 1
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 1
- 229910021591 Copper(I) chloride Inorganic materials 0.000 description 1
- FXHOOIRPVKKKFG-UHFFFAOYSA-N N,N-Dimethylacetamide Chemical compound CN(C)C(C)=O FXHOOIRPVKKKFG-UHFFFAOYSA-N 0.000 description 1
- SUAKHGWARZSWIH-UHFFFAOYSA-N N,N‐diethylformamide Chemical compound CCN(CC)C=O SUAKHGWARZSWIH-UHFFFAOYSA-N 0.000 description 1
- 229960000583 acetic acid Drugs 0.000 description 1
- 230000002730 additional effect Effects 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 239000000460 chlorine Substances 0.000 description 1
- 229910052801 chlorine Inorganic materials 0.000 description 1
- 238000004587 chromatography analysis Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- OXBLHERUFWYNTN-UHFFFAOYSA-M copper(I) chloride Chemical compound [Cu]Cl OXBLHERUFWYNTN-UHFFFAOYSA-M 0.000 description 1
- 229940045803 cuprous chloride Drugs 0.000 description 1
- 125000000664 diazo group Chemical group [N-]=[N+]=[*] 0.000 description 1
- CCAFPWNGIUBUSD-UHFFFAOYSA-N diethyl sulfoxide Chemical compound CCS(=O)CC CCAFPWNGIUBUSD-UHFFFAOYSA-N 0.000 description 1
- 238000003682 fluorination reaction Methods 0.000 description 1
- 239000012362 glacial acetic acid Substances 0.000 description 1
- 230000026030 halogenation Effects 0.000 description 1
- 238000005658 halogenation reaction Methods 0.000 description 1
- 239000004009 herbicide Substances 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 239000000376 reactant Substances 0.000 description 1
- 230000035484 reaction time Effects 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000012808 vapor phase Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C17/00—Preparation of halogenated hydrocarbons
- C07C17/093—Preparation of halogenated hydrocarbons by replacement by halogens
- C07C17/20—Preparation of halogenated hydrocarbons by replacement by halogens of halogen atoms by other halogen atoms
- C07C17/202—Preparation of halogenated hydrocarbons by replacement by halogens of halogen atoms by other halogen atoms two or more compounds being involved in the reaction
- C07C17/208—Preparation of halogenated hydrocarbons by replacement by halogens of halogen atoms by other halogen atoms two or more compounds being involved in the reaction the other compound being MX
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/50—Improvements relating to the production of bulk chemicals
- Y02P20/582—Recycling of unreacted starting or intermediate materials
Definitions
- This invention relates to a method for the preparation of 3-chloro-4,5-difluorobenzotrifluoride.
- the compound is useful as an intermediate in the preparation of various chemical products, in particular in the preparation of substituted diphenyl ethers having herbicidal properties.
- step 4 of the prior art route of synthesis that is, the reaction of KF with 3,4,5-trichlorobenzotrifluoride, leads to the formation of an isomeric mixture of 3-chloro-4,5-difluorobenzotrifluoride and 4-chloro-3,5-difluorobenzotrifluoride, and thus requires additional separation procedures.
- step (c) may be carried out at a temperature of about 170° to about 270° Celsius and preferably about 200° to about 270° Celsius and in the presence of a solvent, such as N-methyl-2-pyrrolidone, sulfolane, N,N-dimethylformamide, N,N-dimethyl- acetamide, N,N-diethylformamide, dimethylsulfoxide, diethylsulfoxide, dipropylsulfoxide, dioctylsulfoxide, dimethylsulfone, diethylsulfone, diphenylsulfone, and the like, and mixtures thereof.
- a solvent such as N-methyl-2-pyrrolidone, sulfolane, N,N-dimethylformamide, N,N-dimethyl- acetamide, N,N-diethylformamide, dimethylsulfoxide, diethylsulfoxide, dipropylsulfoxide, dio
- the proportions of reactants may vary considerably. It is preferred however, to provide a stoichiometric excess of potassium fluoride and most preferably a molar ratio of about 2:1 to about 10:1 of potassium fluoride:fluoro-dichlorobenzotrifluoride.
- halogenation exchange that forms the basis of the process of the invention may be accelerated by the addition of cesium fluoride to the reaction mixture.
- the amount of cesium fluoride that may be incorporated in the reaction mixture may vary considerably, but will typically be in the range of about 0.1 percent to about 10 percent by weight based on the weight of KF.
- the process of the invention may be efficiently operated on a continuous basis with reaction product being removed by distillation and starting material added slowly (in addition to starting material recycled and/or returned by reflux) to compensate for that consumed in the reaction.
- the process is preferably carried out under reflux conditions at atmospheric pressure.
- Product distillate is preferably removed at a vapor temperature of between the boiling points of the starting 3,5-dichloro-4-fluorobenzotrifluoride (b.p. 166° Celsius) and that of the product 3-chloro-4,5-difluorobenzotrifluoride (b.p. 131-132° Celsius) to preferentially remove the 3-chloro-4,5-difluorobenzotrifluoride and any by-product 3,4,5-trifluorobenzotrifluoride (b.p. 98° Celsius). It is most preferred to remove the distillate at a vapor temperature of about 148° to about 153° Celsius.
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)
Abstract
In the synthesis of 3-chloro-4,5-difluorobenzotrifluoride by reaction of KF with 3,5-dichloro-4-fluorobenzotrifluoride, the production of undesirable by-products, especially over-fluorinated materials such as trifluorobenzotrifluoride is minimized when the reaction is run at a temperature of 196° to 206° Celsius in the presence of N-methyl-2-pyrrolidone.
Description
- This invention relates to a method for the preparation of 3-chloro-4,5-difluorobenzotrifluoride. The compound is useful as an intermediate in the preparation of various chemical products, in particular in the preparation of substituted diphenyl ethers having herbicidal properties.
- Various methods for the preparation of 3-chloro-4,5-difluorobenzotrifluoride have been described in the literature. One such method, disclosed in U.S. Patent No. 4,388,472 to Cartwright et al, involves the steps of (1) reacting chlorine with p-trifluoromethylaniline in glacial acetic acid to form 2,6-dichloro-4-trifluoromethylaniline; (2) diazotization of the latter; (3) reaction of the diazo product with cuprous chloride in concentrated hydrochloric acid to form 3,4,5-trichlorobenzotrifluoride and (4) reaction with KF to form 3-chloro-4,5-difluorobenzotrifluoride.
- Such methods, although useful for laboratory preparations are less suitable for commercial scale preparations. The starting material, p-trifluoromethylaniline, is expensive. Furthermore, the diazotization reaction is expensive and not readily adaptable to commercial scale. Furthermore, step 4 of the prior art route of synthesis, that is, the reaction of KF with 3,4,5-trichlorobenzotrifluoride, leads to the formation of an isomeric mixture of 3-chloro-4,5-difluorobenzotrifluoride and 4-chloro-3,5-difluorobenzotrifluoride, and thus requires additional separation procedures. U.S. Patent No. 4,384,135 to Cartwright et al discloses the reaction of 3,4,5-trichlorobenzotrifluoride with KF to form 3-chloro-4,5-difluorobenzotrifluoride. The patentees further disclose the use of 3-chloro-4,5-difluorobenzotrifluoride as an intermediate in the subsequent preparation of a fluorine- containing diphenyl ether herbicide. U.S. Patent No. 4,582,948 discloses a process for the preparation of 3-chloro-4,5-difluorobenzotrifluoride by the vapor phase chloro denitration of 3,4-difluoro-5-nitrobenzotrifluoride.
- In U.S. Patent No. 4,590,315 to Maul et al there is disclosed a process for the preparation of 3-chloro-4,5-difluorobenzotrifluoride comprising the steps of (a) reacting an alkali metal fluoride with 4-chloro-3,5-dinitrobenzotrifluoride to form 4-fluoro-3,5-dinitrobenzotrifluoride; (b) chloro denitrating the 4-fluoro product of step (a) to form 3,5-dichloro-4-fluorobenzotrifluoride; and (c) reacting the 3,5-dichloro-4-fluorobenzotrifluoride compound prepared in step (b) with an alkali metal fluoride to form 3-chloro-4,5-difluorobenzotrifluoride. The patentees suggest that the fluorination reaction of step (c) may be carried out at a temperature of about 170° to about 270° Celsius and preferably about 200° to about 270° Celsius and in the presence of a solvent, such as N-methyl-2-pyrrolidone, sulfolane, N,N-dimethylformamide, N,N-dimethyl- acetamide, N,N-diethylformamide, dimethylsulfoxide, diethylsulfoxide, dipropylsulfoxide, dioctylsulfoxide, dimethylsulfone, diethylsulfone, diphenylsulfone, and the like, and mixtures thereof. The patentees recommend higher boiling solvents, such as sulfolane as preferred since it is preferred to carry out the reaction at higher temperatures. The reaction disclosed leads to the formation of substantial quantities of 3,4,5-trifluorobenzotrifluoride as an unwanted by-product.
- Although prior art methods for the preparation of 3-chloro-4,5-difluorobenzotrifluoride are known and are commercially useful, such processes are characterized by the disadvantage of formation of unwanted by-products. The formation of such by-products, especially 3,4,5-trifluorobenzotrifluoride, results not only in an economic disadvantage with respect to efficient utilization of starting materials and the necessity of added separation steps to remove such by-products, but also an additional disposal problem dictated by present day environmental considerations. Those skilled in the art will appreciate the need for a process that approaches zero environmental discharge.
- Accordingly, it is an object of this invention to provide a process for the preparation of high purity 3-chloro-4,5-difluorobenzotrifluoride that is well-suited for both laboratory and commercial scale preparations in that it is characterized by minimal production of undesired by-products, especially trifluorobenzotrifluoride, and avoidance of the attendant environmental problems.
- It has now been found that, in the synthesis of 3-chloro-4,5-difluorobenzotrifluoride by reaction of potassium fluoride with 3,5-dichloro-4-fluorobenzotrifluoride, the production of undesirable by-products, especially over-fluorinated materials such as trifluorobenzotrifluoride is minimized when the reaction is run at a temperature of about 196° to about 206° Celsius in the presence of N-methyl-2-pyrrolidone.
- The proportions of reactants may vary considerably. It is preferred however, to provide a stoichiometric excess of potassium fluoride and most preferably a molar ratio of about 2:1 to about 10:1 of potassium fluoride:fluoro-dichlorobenzotrifluoride.
- It has been found that the halogenation exchange that forms the basis of the process of the invention may be accelerated by the addition of cesium fluoride to the reaction mixture. The amount of cesium fluoride that may be incorporated in the reaction mixture may vary considerably, but will typically be in the range of about 0.1 percent to about 10 percent by weight based on the weight of KF.
- The process of the invention may be efficiently operated on a continuous basis with reaction product being removed by distillation and starting material added slowly (in addition to starting material recycled and/or returned by reflux) to compensate for that consumed in the reaction.
- The process is preferably carried out under reflux conditions at atmospheric pressure. Product distillate is preferably removed at a vapor temperature of between the boiling points of the starting 3,5-dichloro-4-fluorobenzotrifluoride (b.p. 166° Celsius) and that of the product 3-chloro-4,5-difluorobenzotrifluoride (b.p. 131-132° Celsius) to preferentially remove the 3-chloro-4,5-difluorobenzotrifluoride and any by-product 3,4,5-trifluorobenzotrifluoride (b.p. 98° Celsius). It is most preferred to remove the distillate at a vapor temperature of about 148° to about 153° Celsius.
- When the preparation of 3-chloro-4,5-difluorobenzotrifluoride by reaction of potassium fluoride with 3,5-dichloro-4-fluorobenzotrifluoride was carried out in accordance with the parameters set forth above, that is, in the presence of N-methyl-2-pyrrolidone and at a reaction temperature of about 196° to about 206° Celsius, a product distillate containing 57.5 percent of the desired 3-chloro-4,5-difluorobenzotrifluoride and 0.26 percent 3,4,5-trifluorobenzotrifluoride (GLC analysis, area percent) was produced. By contrast, when the reaction was run in sulfolane, at a temperature of about 192° to 216° Celsius, a product distillate containing 53-60 percent 3-chloro-4,5-difluorobenzotrifluoride and 5-10 percent 3,4,5-trifluorobenzotrifluoride. Carrying out the reaction in N-methyl pyrrolidone at a temperature of 188° to 190° Celsius resulted in a product distillate containing 88-89 percent 3-chloro-4,5-difluorobenzotrifluoride and 2-5 percent 3,4,5-trifluorobenzotrifluoride. Thus, it will be seen that the preparations of 3-chloro-4,5-difluorobenzotrifluoride in accordance with the present invention, is especially advantageous in minimizing the production of undesired over-fluorinated materials and avoidance of the attendant disposal problems.
- The following specific examples are provided to further illustrate this invention and the manner in which it may be carried out. It will be understood, however, that the specific details given in the examples have been chosen for purpose of illustration and are not to be construed as a limitation on the invention. In the examples, unless otherwise indicated, all parts and percentages are by weight and all temperatures are in degrees Celsius.
- A mixture of 161 parts of anhydrous potassium fluoride in 671 parts of n-methyl pyrrolidone was heated to about 196°C and 94.4 parts of 3,5-dichloro-4-fluorobenzotrifluoride was added. An additional 155.6 parts of 3,5-dichloro-4-fluorobenzotrifluoride was added slowly over a reaction period of 34.5 hours during which the temperature of the reaction mixture was 196°-202°C. After 23.5 hours of reaction time, 4.2 parts of CsF was added to the reaction mixture. During the reaction, temperature of the refluxing vapors was maintained at 150°-151°C and a total of 168.2 parts of distillate was removed in periodic sampling and analyzed by gas chromatographic methods with the results shown in Table 1.
Claims (6)
1. A process for the preparation of 3-chloro-4,5-difluorobenzotrifluoride which comprises reacting 3,5-dichloro-4-fluorobenzotrifluoride with potassium fluoride in the presence of N-methyl-2-pyrrolidone at a temperature of about 196° to about 206° Celsius.
2. A process according to Claim 1 carried out in the presence of cesium fluoride.
3. A process according to Claim 1 wherein the molar ratio of potassium fluoride:3,5-dichloro-4-fluorobenzotrifluoride is about 2:1 to about 10:1.
4. A process according to Claim 1 carried out under reflux conditions.
5. A process according to Claim 4 wherein the product is removed by distillation at a vapor temperature of about 131° to 166° Celsius.
6. A process according to Claim 4 wherein the produce is removed by distillation at a vapor temperature of about 148° to about 153° Celsius.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US4417487A | 1987-04-30 | 1987-04-30 | |
| US44174 | 1987-04-30 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| EP0289036A1 true EP0289036A1 (en) | 1988-11-02 |
Family
ID=21930900
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP88106896A Withdrawn EP0289036A1 (en) | 1987-04-30 | 1988-04-29 | Preparation of 3-chloro-4,5-difluorobenzotrifluoride |
Country Status (3)
| Country | Link |
|---|---|
| EP (1) | EP0289036A1 (en) |
| JP (1) | JPS63284139A (en) |
| BR (1) | BR8801947A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4937396A (en) * | 1988-11-28 | 1990-06-26 | The Dow Chemical Company | Preparation of 3,4-difluorobenzotrifluoride |
| DE102009049419A1 (en) * | 2009-10-14 | 2011-04-28 | Saltigo Gmbh | Producing 3-chloro-4,5-difluorbenzotrifluoride comprises reacting 3,4,5-trichlorobenzotrifluoride with a fluoride source in the presence of a catalyst and distillatively separating 3-chloro-4,5-difluorbenzotrifluoride from reaction mixture |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4590315A (en) * | 1984-10-15 | 1986-05-20 | Occidental Chemical Corporation | Process for the preparation of halo aromatic compounds |
-
1988
- 1988-04-22 BR BR8801947A patent/BR8801947A/en unknown
- 1988-04-26 JP JP63103746A patent/JPS63284139A/en active Pending
- 1988-04-29 EP EP88106896A patent/EP0289036A1/en not_active Withdrawn
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4590315A (en) * | 1984-10-15 | 1986-05-20 | Occidental Chemical Corporation | Process for the preparation of halo aromatic compounds |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4937396A (en) * | 1988-11-28 | 1990-06-26 | The Dow Chemical Company | Preparation of 3,4-difluorobenzotrifluoride |
| DE102009049419A1 (en) * | 2009-10-14 | 2011-04-28 | Saltigo Gmbh | Producing 3-chloro-4,5-difluorbenzotrifluoride comprises reacting 3,4,5-trichlorobenzotrifluoride with a fluoride source in the presence of a catalyst and distillatively separating 3-chloro-4,5-difluorbenzotrifluoride from reaction mixture |
| DE102009049419B4 (en) * | 2009-10-14 | 2012-03-08 | Saltigo Gmbh | Improved process for the preparation of 3-chloro-4,5-difluorobenzotrifluoride |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS63284139A (en) | 1988-11-21 |
| BR8801947A (en) | 1988-11-22 |
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